Question

我正在从包含一些看起来像这样的汇编指令的文本文件中读入

[label]操作码[arg1] [，arg2]

现在我只是处于阅读标签的阶段，但是当我从文件中读取并将标签输入到数组中时，我得到一些不应该存在的空行。这是我的代码

#include <string>
#include <iostream>
#include <cstdlib>
#include <string.h>
#include <fstream>
#include <stdio.h>



using namespace std;


int main(int argc, char *argv[])
{
// If no extra file is provided then exit the program with error message
if (argc <= 1)
{
    cout << "Correct Usage: " << argv[0] << " <Filename>" << endl;
    exit (1);
}

// Array to hold the registers and initialize them all to zero
int registers [] = {0,0,0,0,0,0,0,0};

string memory [16000];

string Symtablelab[1000];
int Symtablepos[1000];


string line;
string label;
string opcode;
string arg1;
string arg2;


// Open the file that was input on the command line
ifstream myFile;
myFile.open(argv[1]);


if (!myFile.is_open())
{
    cerr << "Cannot open the file." << endl;
}

int counter = 0;
int i = 0;
int j = 0;

while (getline(myFile, line, '\n'))
{

    if (line[0] == '#')
    {
        continue;
    }


    if (line[0] != '\t' && line[0] != ' ')
    {

        string delimeters = "\t";

        int current;
        int next = -1;


        current = next + 1;
        next = line.find_first_of( delimeters, current);
        label = line.substr( current, next - current );

        Symtablelab[i] = label;

        cout << Symtablelab[i] << endl;

        i++;

    }


}


return 0;
}

我从这段代码得到的输出是：

blank line
TOP
VAL
TAN
blank line

我应该得到：

TOP
VAL
TAN

以下是我正在阅读的示例文本文件

# Sample Input

    LA 1,3
    LA 2,1
TOP     NOP
    ADDR 3,1
    ST 3, VAL
    CMPR 3,4
    JNE TOP
    P_INT 1,VAL
    P_REGS
    HALT
VAL     INT 0
TAN     LA  2,1

Answer 1

评论后的空白行和结尾的隐含空白行导致了您的问题。您应该在注释检查后添加一个空白行。

if (line.length == 0) {
  continue;
}

使用find_first_of（）和substr（）分隔一个字符串，但输出不正确

1 个答案: